Abstract:

This study addressed the microwave-assisted enzymatic extraction of gypenosides from the whole plants of
Gynostemma pentaphyllum as an improvement over the traditional water extraction method, giving a lower extraction yield.
Response surface method based on Box-Behnken design was used to optimize the ratio of pectinase to hemicellulase to
cellulose for their combined use in the extraction of gypenosides as well as process parameters. The results showed that
enzyme dosage, hydrolysis temperature, hydrolysis time and microwave irradiation time were identified as main variables
that influence extraction efficiency. The optimum values for these 4 independent variables were 1.8%, 52 ℃, 2 h and 4 min,
respectively. The yield of gypenosides was 7.88% under these conditions, which was increased by 68% compared with
that obtained with the traditional water extraction method. Due to its low extraction temperature and simple operation, this
method has a good prospect of industrial application.

Key words: microwave, multi-enzymatic method, response surface methodology, gypenosides